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15f3f1fe57
qemu/include/block/block-global-state.h
Kevin Wolf 15f3f1fe57 block: Mark bdrv_get_xdbg_block_graph() and callers GRAPH_RDLOCK 
This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_get_xdbg_block_graph() need to hold a reader lock for the graph
because it accesses the children list of a node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20230929145157.45443-10-kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2023-10-12 16:31:33 +02:00

308 lines
13 KiB
C
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/*
* QEMU System Emulator block driver
*
* Copyright (c) 2003 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef BLOCK_GLOBAL_STATE_H
#define BLOCK_GLOBAL_STATE_H
#include "block/block-common.h"
#include "qemu/coroutine.h"
#include "qemu/transactions.h"
/*
* Global state (GS) API. These functions run under the BQL.
*
* If a function modifies the graph, it also uses drain and/or
* aio_context_acquire/release to be sure it has unique access.
* aio_context locking is needed together with BQL because of
* the thread-safe I/O API that concurrently runs and accesses
* the graph without the BQL.
*
* It is important to note that not all of these functions are
* necessarily limited to running under the BQL, but they would
* require additional auditing and many small thread-safety changes
* to move them into the I/O API. Often it's not worth doing that
* work since the APIs are only used with the BQL held at the
* moment, so they have been placed in the GS API (for now).
*
* These functions can call any function from this and other categories
* (I/O, "I/O or GS", Common), but must be invoked only by other GS APIs.
*
* All functions in this header must use the macro
* GLOBAL_STATE_CODE();
* to catch when they are accidentally called without the BQL.
*/
void bdrv_init(void);
BlockDriver *bdrv_find_protocol(const char *filename,
bool allow_protocol_prefix,
Error **errp);
BlockDriver *bdrv_find_format(const char *format_name);
int coroutine_fn GRAPH_UNLOCKED
bdrv_co_create(BlockDriver *drv, const char *filename, QemuOpts *opts,
Error **errp);
int co_wrapper bdrv_create(BlockDriver *drv, const char *filename,
QemuOpts *opts, Error **errp);
int coroutine_fn GRAPH_UNLOCKED
bdrv_co_create_file(const char *filename, QemuOpts *opts, Error **errp);
BlockDriverState *bdrv_new(void);
int bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
Error **errp);
int bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
Error **errp);
int bdrv_replace_child_bs(BdrvChild *child, BlockDriverState *new_bs,
Error **errp);
BlockDriverState *bdrv_insert_node(BlockDriverState *bs, QDict *node_options,
int flags, Error **errp);
int bdrv_drop_filter(BlockDriverState *bs, Error **errp);
BdrvChild * no_coroutine_fn
bdrv_open_child(const char *filename, QDict *options, const char *bdref_key,
BlockDriverState *parent, const BdrvChildClass *child_class,
BdrvChildRole child_role, bool allow_none, Error **errp);
BdrvChild * coroutine_fn no_co_wrapper
bdrv_co_open_child(const char *filename, QDict *options, const char *bdref_key,
BlockDriverState *parent, const BdrvChildClass *child_class,
BdrvChildRole child_role, bool allow_none, Error **errp);
int bdrv_open_file_child(const char *filename,
QDict *options, const char *bdref_key,
BlockDriverState *parent, Error **errp);
BlockDriverState * no_coroutine_fn
bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp);
BlockDriverState * coroutine_fn no_co_wrapper
bdrv_co_open_blockdev_ref(BlockdevRef *ref, Error **errp);
int bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
Error **errp);
int bdrv_set_backing_hd_drained(BlockDriverState *bs,
BlockDriverState *backing_hd,
Error **errp);
int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
const char *bdref_key, Error **errp);
BlockDriverState * no_coroutine_fn
bdrv_open(const char *filename, const char *reference, QDict *options,
int flags, Error **errp);
BlockDriverState * coroutine_fn no_co_wrapper
bdrv_co_open(const char *filename, const char *reference,
QDict *options, int flags, Error **errp);
BlockDriverState *bdrv_new_open_driver_opts(BlockDriver *drv,
const char *node_name,
QDict *options, int flags,
Error **errp);
BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
int flags, Error **errp);
BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
BlockDriverState *bs, QDict *options,
bool keep_old_opts);
void bdrv_reopen_queue_free(BlockReopenQueue *bs_queue);
int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp);
int bdrv_reopen(BlockDriverState *bs, QDict *opts, bool keep_old_opts,
Error **errp);
int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
Error **errp);
BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
const char *backing_file);
void bdrv_refresh_filename(BlockDriverState *bs);
void GRAPH_RDLOCK
bdrv_refresh_limits(BlockDriverState *bs, Transaction *tran, Error **errp);
int bdrv_commit(BlockDriverState *bs);
int bdrv_make_empty(BdrvChild *c, Error **errp);
int bdrv_change_backing_file(BlockDriverState *bs, const char *backing_file,
const char *backing_fmt, bool warn);
void bdrv_register(BlockDriver *bdrv);
int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
const char *backing_file_str);
BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
BlockDriverState *bs);
BlockDriverState *bdrv_find_base(BlockDriverState *bs);
bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
Error **errp);
int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
Error **errp);
void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base);
/*
* The units of offset and total_work_size may be chosen arbitrarily by the
* block driver; total_work_size may change during the course of the amendment
* operation
*/
typedef void BlockDriverAmendStatusCB(BlockDriverState *bs, int64_t offset,
int64_t total_work_size, void *opaque);
int bdrv_amend_options(BlockDriverState *bs_new, QemuOpts *opts,
BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
bool force,
Error **errp);
/* check if a named node can be replaced when doing drive-mirror */
BlockDriverState * GRAPH_RDLOCK
check_to_replace_node(BlockDriverState *parent_bs, const char *node_name,
Error **errp);
int no_coroutine_fn GRAPH_RDLOCK
bdrv_activate(BlockDriverState *bs, Error **errp);
int coroutine_fn no_co_wrapper_bdrv_rdlock
bdrv_co_activate(BlockDriverState *bs, Error **errp);
void bdrv_activate_all(Error **errp);
int bdrv_inactivate_all(void);
int bdrv_flush_all(void);
void bdrv_close_all(void);
void bdrv_drain_all_begin(void);
void bdrv_drain_all_begin_nopoll(void);
void bdrv_drain_all_end(void);
void bdrv_drain_all(void);
void bdrv_aio_cancel(BlockAIOCB *acb);
int bdrv_has_zero_init_1(BlockDriverState *bs);
int bdrv_has_zero_init(BlockDriverState *bs);
BlockDriverState *bdrv_find_node(const char *node_name);
BlockDeviceInfoList *bdrv_named_nodes_list(bool flat, Error **errp);
XDbgBlockGraph * GRAPH_RDLOCK bdrv_get_xdbg_block_graph(Error **errp);
BlockDriverState *bdrv_lookup_bs(const char *device,
const char *node_name,
Error **errp);
bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base);
BlockDriverState *bdrv_next_node(BlockDriverState *bs);
BlockDriverState *bdrv_next_all_states(BlockDriverState *bs);
typedef struct BdrvNextIterator {
enum {
BDRV_NEXT_BACKEND_ROOTS,
BDRV_NEXT_MONITOR_OWNED,
} phase;
BlockBackend *blk;
BlockDriverState *bs;
} BdrvNextIterator;
BlockDriverState * GRAPH_RDLOCK bdrv_first(BdrvNextIterator *it);
BlockDriverState * GRAPH_RDLOCK bdrv_next(BdrvNextIterator *it);
void bdrv_next_cleanup(BdrvNextIterator *it);
BlockDriverState *bdrv_next_monitor_owned(BlockDriverState *bs);
void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
void *opaque, bool read_only);
char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp);
char *bdrv_dirname(BlockDriverState *bs, Error **errp);
void bdrv_img_create(const char *filename, const char *fmt,
const char *base_filename, const char *base_fmt,
char *options, uint64_t img_size, int flags,
bool quiet, Error **errp);
void bdrv_ref(BlockDriverState *bs);
void no_coroutine_fn bdrv_unref(BlockDriverState *bs);
void coroutine_fn no_co_wrapper bdrv_co_unref(BlockDriverState *bs);
void GRAPH_WRLOCK bdrv_schedule_unref(BlockDriverState *bs);
void GRAPH_WRLOCK
bdrv_unref_child(BlockDriverState *parent, BdrvChild *child);
void coroutine_fn no_co_wrapper_bdrv_wrlock
bdrv_co_unref_child(BlockDriverState *parent, BdrvChild *child);
BdrvChild * GRAPH_WRLOCK
bdrv_attach_child(BlockDriverState *parent_bs,
BlockDriverState *child_bs,
const char *child_name,
const BdrvChildClass *child_class,
BdrvChildRole child_role,
Error **errp);
bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp);
void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason);
void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason);
void bdrv_op_block_all(BlockDriverState *bs, Error *reason);
void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason);
bool bdrv_op_blocker_is_empty(BlockDriverState *bs);
int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
const char *tag);
int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag);
int bdrv_debug_resume(BlockDriverState *bs, const char *tag);
bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag);
/**
* Locks the AioContext of @bs if it's not the current AioContext. This avoids
* double locking which could lead to deadlocks: This is a coroutine_fn, so we
* know we already own the lock of the current AioContext.
*
* May only be called in the main thread.
*/
void coroutine_fn bdrv_co_lock(BlockDriverState *bs);
/**
* Unlocks the AioContext of @bs if it's not the current AioContext.
*/
void coroutine_fn bdrv_co_unlock(BlockDriverState *bs);
bool bdrv_child_change_aio_context(BdrvChild *c, AioContext *ctx,
GHashTable *visited, Transaction *tran,
Error **errp);
int bdrv_try_change_aio_context(BlockDriverState *bs, AioContext *ctx,
BdrvChild *ignore_child, Error **errp);
int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz);
int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo);
void GRAPH_WRLOCK
bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, Error **errp);
void GRAPH_WRLOCK
bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp);
/**
*
* bdrv_register_buf/bdrv_unregister_buf:
*
* Register/unregister a buffer for I/O. For example, VFIO drivers are
* interested to know the memory areas that would later be used for I/O, so
* that they can prepare IOMMU mapping etc., to get better performance.
*
* Buffers must not overlap and they must be unregistered with the same <host,
* size> values that they were registered with.
*
* Returns: true on success, false on failure
*/
bool bdrv_register_buf(BlockDriverState *bs, void *host, size_t size,
Error **errp);
void bdrv_unregister_buf(BlockDriverState *bs, void *host, size_t size);
void bdrv_cancel_in_flight(BlockDriverState *bs);
#endif /* BLOCK_GLOBAL_STATE_H */
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